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Half lives of two radioactive elements A and B are 20 minutes and 40 minutes respectively. Initially, the samples have equal number of nuclei. Calculate the ratio of decayed numbers of A and B nuclei after 80 minutes. |
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Answer» Solution :80 minutes = 4 half lives of A = 2 half live of B Let the initial number of nuclei in each sample be N. `N_(A)` after 80 minutes = `(N)/(2^(4))` Number of A NUCLIDES decayed = `(15)/(16)N` `N_(B)` after 80 minutes =` (N)/(2^(4))` Number of B nuclides decayed = `(3)/(4)N` Required RATIO = `(15)/(16) xx (4)/(3) = (5)/(4)` `N_(A) : N_(B) = 5 : 4` |
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